Figure 4
Histological assessment of the effect of RA on epithelial morphology of BBEC cultures. BBEC cultures were grown for 21 days at an ALI with varying concentrations of RA before being fixed and paraffin-embedded using standard histological techniques; samples of ex vivo tissue were also taken from the donor animal. Sections were cut, deparaffinised and stained as described in Fig. 1. Representative images are shown of (i) ex vivo bovine bronchial epithelium, and BBECs grown in the presence of (ii) 0 and (iii) 100 nM RA (see Fig. S4). Quantitative analysis (using ImageJ) of histological sections of BBEC layers grown in the presence of 0, 25, 50, 100 and 250 nM RA (see Fig. S4A), and ex vivo tissue, to assess (D) epithelial thickness and (E) the number of cell layers comprising the epithelium, was performed as described in Fig. 1. Statistical significance was tested using an Ordinary one-way ANOVA: *** = P < 0.001.
